Various production machines presently are available in the shrimp processing industry for processing shrimp. Illustrative of conventional production machines are U.S. Pat. No. 4,769,871, 4,507,825 and 3,751,766, the disclosures, including specification and drawings, of which are incorporated by reference herein. Generally, four or six clamping stations are located on a rotary turret wheel. A shrimp is deposited in a clamp assembly which comprises two components, one of which grips the shrimp body while the remaining component grips the shrimp tail. Once clamped in position, the assembly is rotated past a cutting station where a rotary cutting blade cuts the shrimp shell and meat body along the entire or substantial length or longitudinal axis of the shrimp to expose the shrimp sand vein.
Following the cutting operation, the clamp assembly is rotated to another work station where a brush assembly serves to rake debris from the sand vein area. At a subsequent work station, a plurality of spikes or tines positioned adjacent the clamp assembly are actuated and penetrate the shrimp meat which is exposed following the cutting of the shrimp shell. The spikes coact with the revolving clamp means, which continue to grip the shrimp, and separate the shrimp meat from the shell. Following separation, the spikes or tines are retracted from the meat and the meat is transported to a collecting station while the shell is transported to a further work station where, ultimately, it is released from the clamp assembly and passes into a discharge container.
Shrimp consisting of the flesh body to which the shrimp tail remains attached and from which the sand vein and main portion of the shrimp shell has been removed is referred to in the trade as "tail-on" shrimp. Shrimp which have the shrimp tail removed from the flesh body during the course of processing the shrimp are referred to as "tail-off" shrimp.
Depending upon whether a shrimp is to be a "tail-on" or "tail-off" style dictates where the knife blade enters the shrimp during a cutting operation. For a "tail-off" shrimp, the blade is set to cut along the entire length or longitudinal axis of the shrimp. If a "tail-on" shrimp is desired, the rotary knife blade does not enter the shrimp at the tail section; but, rather, the blade is adjusted relative to a clamp assembly so that only a portion of the shrimp shell is cut.
The mechanism presently available for adjusting the location where a rotary knife blade enters a shrimp for either a "tail-on" or "tail-off" style employs a cam follower which follows a cam path generated by a cam attached to a gear member. The cam follower is connected to a pivotable arm to which the cutter blade is also attached. As the cam follower travels over the cam path, the knife blade will travel a corresponding path which dictates where the knife will enter a shrimp. The cam is adapted to be adjusted to take into account the size of a shrimp to be cut and whether the shrimp is to be processed as "tail-off" or "tail-on."
It has been found that the system for converting a cam assembly from a "tail-on" to a "tail-off" style or otherwise adjusting the cam assembly is not entirely satisfactory in all instances. To provide the appropriate cam adjustment with the system presently available, a retaining pin is removed and a retention gear having the cam fixedly attached thereto is withdrawn from meshing engagement with a corresponding drive gear to a position where the retention gear is adapted to rotate freely. The retention gear then is rotated a distance of one, two, three or more teeth depending upon the size of the shrimp being processed, following which the retention gear is placed back into meshing relationship with the drive gear and the locking hardware is reinserted. Rotation of the retention gear having the cam fixedly attached thereto by movement of several teeth relative to the drive gear serves to alter the cam path when the machine is subsequently actuated so that the rotary cutting blade will travel in an altered path and provided the desired "tail-on" style shrimp.
Similarly, when it is desired to have a "tail-off" style shrimp, the retention gear is rotated some ten or eleven teeth relative to the drive gear following which the retention gear is meshed again with the drive gear. In this adjusted position, the cam permits the rotary blade to cut a shrimp along its entire length.
Unfortunately, the present cam adjusting system suffers from several attendant disadvantages. It has been found that when an operator removes the retention gear from its meshing relationship with the drive gear and rotates it to a desired position, he or she will sometimes forget the number of teeth the gear is rotated. As a result, an operator sometimes becomes confused in the course of an adjusting operation, the effect of which is to generate an erroneous cam follower path. Further, it has been found that the carrying out of the present cam adjustment system, even when performed correctly, involves an inordinate amount of time for the normal operator. In other instances, operators have found the present cam adjustment system to be too difficult and tedious. Additionally, irrespective of what style shrimp is desired, i.e., "tail-off" or "tail-on," adjustment by way of moving the retention gear a finite number of teeth relative to the drive gear is always required. Moreover, it has been found that, in some instances, where an operator perceives the adjusting system to be either too slow, complex or tedious, the operator simply does not perform the necessary cam adjustment which results in the wrong style shrimp being processed.
FInally, when the present cam adjustment system is set for "tail-off" style processing, the cam rotates unnecessarily and causes the cam follower to travel over the cam path unnecessarily, which, in turn, causes the pivotable arm to which the cutter blade is attached to travel unnecessarily over a corresponding path. All this unnecessary travel results in excess wear and tear on these moving parts.
What is desired is to have a means for easily adjusting the position where the shrimp cutting knife or blade will enter the shrimp for either a "tail-on" or "tail-off" style and also for taking into account the particular size of shrimp to be cut. It is also desired that the cam adjustment be accomplished in a relatively short period of time. Further, it is desired to have a knife adjusting system which is more efficient and reliable than the adjusting system presently available. Moreover, it is desired to have a relatively simple knife blade adjusting system whereby an operator of ordinary skill can relatively quickly and easily adjust the location where a cutter blade or knife enters a shrimp to achieve a desired shrimp style. Finally, it is desired to have an adjusting system wherein the cam member can be readily placed in an inoperative position when a "tail-off" style shrimp is being processed, such that unnecessary travel of the cam follower and the resulting wear can be avoided.